Aroma and Antioxidant Activity – Distinguished by Drying Conditions, Harvest Maturity and Origin of Litsea cubeba (Lour.) Pers. in Taiwan

• Main Authors: Kwok-Yuk Tam, 譚國鋈
• Other Authors: Shu-Yen Lin
• Format: Others
• Language: zh-TW
• Published: 2019
• Online Access: http://ndltd.ncl.edu.tw/handle/b39r66

碩士 === 國立臺灣大學 === 園藝暨景觀學系 === 107 === Litsea cubeba (Lour.) Pers. is a traditional spice ‘Maqaw’ used by Taiwan aborigine Tayal, which the fruit is lemon, pepper and ginger scented. Fruit of L. cubeba usually preserved by drying but the effect of drying to its quality is not known. On the other hand, fruit maturity and its origin are also factors. This investigation analysed the quality of fruits with various drying treatments, fruit ripeness and origin, in order to estimate its most suitable drying method, harvest maturity and usage through their aromatic components, polyphenols content and antioxidative activities. Fruit of L. cubeba was dried by -50℃ freeze drying, 40℃, 60℃, 80℃ oven drying and sun drying. Main aroma component in all drying treatments is citral. Monoterpenoids, polyphenols and antioxidative activity are conserved most by -50℃ freeze drying, which total polyphenols content is 17.95±0.39 mg/g, DPPH and ABTS radical scavenging power are 33.61±4.48% and 71.36±2.21% repectively. Oven drying with 80℃shorten the drying time effectively to 9 hours and keeps the specific aroma, polyphenols and antioxdative activity. Its total polyphenols content is 14.44±0.30 mg/g, DPPH and ABTS radical scavenging power are 20.97±2.94% and 58.36±3.79% respectively. Unripe fruits contain more fresh scented monoterpenoids, but ripen fruits have higher polyphenols content, antioxidative activity, and the ratio of citral. The DPPH radical scavenging power raised from 49.18±2.49% and 53.36±0.47% to 66.10±1.21% and 64.97±1.74%. 9 fruits from 4 production areas have 13 same aroma compounds. Although total polyphenols content of fruits from Meifeng is the highest, Hualian no. 2 and Wulai wild fruit performed the highst antioxidative activities, which DPPH radical scavenging power are 63.25±5.52% and 66.22±0.36%, ABTS radical scavenging power are 91.15±1.39% and 92.20±0.44%, respectively. All parts from L. cubeba can be used. Total polyphenols content and antioxidative activities of leaf, stem, fruit pedicel and flowers are much higher than fruits. In three individual of L. cubeba trees, fruit extracts perform 43.71±1.52% to 63.25±5.52% DPPH scavenging power, leaf and stem are 75.56±0.95% to 82.62±0.42%. ABTS radical scavenging power of 2X diluted fruit extract are 85.26±4.11% to 91.15±1.39%, fruit pedicel and flower 32X extracts still have 57.32±2.98% to 64.00±1.96% scavenging powers.